At the beginning of the mission, go left up the stairs and through the doors. Expect resistance at the top. To get to each artifact you will need to deactivate the containment. After locating the artifact, eliminate the Cerberus troops and collect the artifact, then return to the landing pad and place the artifact onto the shuttle for extraction, but look around for useful items first.

From the initial landing pad and up the ramps, you'll find the Sniper Rifle Enhanced Scope just inside the first archway on the left on the floor. Directly to the right on the console are credits (3,000). Ahead in the room in the hall on the left is a medical station (150 experience). In the corner of the room is a journal entry (18 experience). In the hallway on the right there are more credits (4,000) to the left of the ammo pile. Down the hallway past the reaper artifact (not down the stairs on the left or the right) is a small room with a failed medi-gel experiment. Return to where you started, and go right and pick up the credits (3,000) right past the doorway. Go down the stairs and in the corner is a journal entry (18 experience).

Go back into the base to locate the next artifact: there will now be more Cerberus troops, this time with turrets. You'll find the second artifact on the lowest level. Once you locate it, be careful as you deactivate its containment because two Cerberus troopers will drop in right near you during the process. Remember to pick up the artifact itself once you've dealt with the new arrivals. Shepard will now radio Cortez who turns out to have been driven away from the landing pad by Cerberus fire.

You must now hold out against a continuous stream of Cerberus troops until Cortez is able to return. Several radio conversations along the way will provide checkpoints to let you know you're making progress. When Shepard says to just "reload and keep firing", do exactly that. After you down more enemies, Shepard will suggest keeping the landing pad clear. You should now return to the room where the shuttle originally dropped out, as this will speed the activation of the next segment. In the third radio check-in, Cortez will say it will just be a bit longer - at this point you should continue to clear the landing pad, but if the firefight gets too hot and you need to pull back there is no penalty.

Finally, you'll see the shuttle pull up and Cortez will tell you to get on. From this point forward, successfully reaching and activating the shuttle will instantly end the mission with victory, regardless of the number of enemies remaining. You may find, however, that you need to clear more enemies away in order to reach the shuttle safely, and there is no pressure preventing you from doing so.